Technical Field
The present disclosure relates to the field of overvoltage protection and, more particularly, to in situ overvoltage protection for active bridge applications.
Description of the Related Art
Active switches such as MOS transistors, bipolar transistors, and IGBTs are used in bridge circuits for controlled rectification and inverter stages.
One common type of bridge circuit is the H-bridge. The H-bridge is formed by connecting two half bridges in parallel. Typically, each half bridge includes two active switches in series. A 3-phase bridge, typically used in brushless DC motor control, is formed by connecting three half bridges in parallel.
In applications where AC mains are rectified and filtered to generate a DC bus voltage supply for powering the active bridge inverter, overvoltage protection schemes are typically employed to protect the bridge circuit and the load from overvoltage conditions on the AC main.
Existing methods are usually less effective for persistent or long duration overvoltage conditions or add significant cost and hardware penalties.